These truths are evident as they apply to the Rangers’ two second-year defensemen whose immediate futures took divergent paths yesterday.

Twenty-year-old Michael Del Zotto’s response to being sent down to the AHL Whale yesterday will be as critical to his future with the Rangers as 26-year-old Matt Gilroy’s response to being named to a top-six spot will be to his future with the Blueshirts.

Make no mistake. This move — in which rookie Ryan McDonagh was promoted for the purpose of evaluation over the next few days of practice — is primarily about Del Zotto, who seems to have gone off the rails a little bit after an all-rookie season in which he made an early splash that might have brought too much praise too soon.

But it is also about Gilroy getting the opportunity to show his stuff without always looking over his shoulder during the final year of his contract.

“We have to worry about development and winning hockey games,” coach John Tortorella said on a late afternoon conference call. “The way Gilly has played, he’s gotten better, both in the offensive end and he’s improved defensively.

“Right now we feel this six [with Marc Staal, Dan Girardi, Michal Rozsival, Steve Eminger, Michael Sauer] gives us the best chance to win.”

Right from the start, when Del Zotto was named NHL rookie of the month for October 2009 as a 19-year-old, Tortorella would approvingly cite the young man’s cocky demeanor but always with a caveat, stressing how important it would be for him to stay on the right side of the line by respecting the process of becoming a pro.

The inference can be drawn that Del Zotto crossed a double white line this year, when he sat out four straight times — the first and last as scratches, the middle two for health reasons, though he’d have been scratched regardless — until reinstated for a jittery appearance in Sunday’s 3-0 loss in Florida.

“It’s seeing improvement in his mindset and play on the ice,” Tortorella said when asked what Del Zotto needs to show in order to earn a recall. “It’s him understanding how to think the game, to think preparation, and also bring that to within his game as far as the minutes he gets there.”

Then Tortorella was asked about Del Zotto’s general reaction to the news.

“Sometimes players don’t agree with it, but it’s not up to the player,” Tortorella said. “This is a 20-year-old kid and sometimes they don’t see it right now, but eventually he is going to realize this is good for him.

“It’s going to be good for him as a player and good for us as an organization.”

But it will only be positive if Del Zotto reports to the Whale with a positive attitude. This will only be a constructive experience if he treats this in the manner the Islanders’ 21-year-old, third-year forward Josh Bailey did when he was assigned to AHL Bridgeport earlier this season.

Gilroy is approaching the end of the two-year, $3.5 million deal he signed as a free agent out of Boston University in April 2009. He is coming up on restricted free agency, owed a $2.1 million qualifier that is exceptionally pricey for a third-pair defenseman.

Impressive work the rest of the way, however, could earn him a multi-year offer at a smaller number while also making him more attractive to the rest of the league.